1. Field of the Invention
The present invention relates to a drive controller including a plurality of drive modules for driving a plurality of actuators, and a method for determining the drive module in the drive controller.
2. Description of the Related Art
One of control systems that use a plurality of actuators is known as an industrial robot. Such a robot is for example equipped with a robot main body working as a polyarticular type of robot member, a controller controlling the robot main body, and a teaching pendant that can be used to provide necessary commands to the controller.
In this conventional configuration, the robot main body usually has one or more manipulators each using a plurality of joints, at each of which a drive motor is disposed. The drive motors are driven respectively by drive signals from drive circuits (drivers) disposed in the controller. It is frequent that each of the driver circuits, which is for example an inverter circuit, is formed as an independent module. The reason that the drive circuits are required in the form of modules is as follows.
In manufacturing the robot system, the configurations of the robot main body and the controller are not always in one-to-one correspondence. It is often that each of the robot main body and the controller is manufactured as a separate product for use in an appropriate combination of the main body and controller. Various ratings of drive motors (such as 750 W, 400 W, 200 W, 100 W, and 50 W) are used to drive each joint of the robot main body. Each inverter circuit incorporated in the controller thus needs to have current capacitance corresponding to the rating of each drive motor.
Since there are the above-described requirements, the inverter circuits are typically configured as modules detachable to the unit frame of the controller. Any appropriate inverter circuit is selected for use according to the specification of the robot main body that is to be controlled by the controller.
For the conventional controller, however, mainly the operators check visually if the type of the inverter circuit to be incorporated in the controller corresponds appropriately to the rating of the drive motor on the robot main body. A problem thus arises in that the robot main body may start its operation if the check is neglected, even if the inverter circuit corresponds in ratings to the drive motor in an appropriate manner (that is, the inverter circuit is not matched to the drive motor). If the robot main body continues to operate regardless of the inappropriate correspondence (mismatched state) between the inverter circuit and the drive motor, the inverter circuit may be overloaded.